VFS objects aio_pthread and streams_xattr for CIFS shares

[stualden]

I need to set up some CIFS shares manually because the wizard can't set up my pool the way I need it. But I did run the wizard first to try to observe and understand the default settings.

With the wizard, CIFS shares are set up with VFS objects of aio_pthread and streams_xattr (and no other VFS objects, it appears).

When setting up a CIFS share manually, the only VFS objects listed as available are the five described in the documentation; aio_pthread and streams_xattr are not on the list.

I can see from previous forum postings that aio_pthread may no longer be useful (and I'm not sure what it does anyway). I think I would like to have streams_xattr, though, to try to preserve any small ADSes which exist in my current NTFS files. (I will admit that I don't know what's in those streams, or whether I really need them, but for example, about half of my music files have them, so I am slightly anxious about losing them.)

My questions:

• Is it intentional that the wizard puts these two objects in there, but that they are not available on the list when manually setting up the CIFS share?
• If not intentional, should they appear on the list (along with the other five), or alternatively, should they be removed from the wizard?
• If I want to include streams_xattr, is it possible to specify an auxiliary parameter that would accomplish that (and not trash any other needed parameters)? Would that parameter simply be "vfs objects = streams_xattr" or is it more complicated than that?
• Or, should I just chill and let those ADSes disappear?

I understand that it's foolish to make direct edits to smb.conf so I'm not going there.

Thanks,

--Stu

 

[cyberjock]

What "list" are you even referring to when you pose your questions?

 

[stualden]

Table 10.4b in the documentation ("Available VSB Modules"), or equivalently, the list of available VSB Objects on the "Add Windows (CIFS) Share" dialog.

I now realize I wasn't clear about which wizard is which:

--When you set up a share "manually" (i.e., with the CIFS share creation wizard), the dialog lists the five available objects, and you can move any of them you want over to the "Selected" list to make sure they're included.

--If on the other hand you set up the shares via the main setup wizard (the wizard accessed from the main menu which creates datasets and shares them as one combined process), and afterwards view the properties of the share, the two objects we're discussing (which are not among the five documented objects) are sitting there on the Selected list.

 

[stualden]

By using the auxiliary parameter "vfs objects = streams_xattr" I've been able to ensure that ADSes are copied across correctly. I no longer get warnings about not being able to copy "certain properties," and a spot-check of files copied to the CIFS share and back to NTFS shows that the ADSes are still there (and untouched).

So, I think that resolves my immediate issue, but I'd still like to know how to report this for potential improvement in a future release. Is it reasonable to request that streams_xattr show up on the list of available modules when setting up a CIFS share? I think most CIFS users would find it helpful (and it would be consistent with the "automatic" inclusion of streams_xattr in the setup wizard). Some documentation of how it allows the preservation of ADSes might be helpful as well.

 

[dlavigne]

You could create a feature request explaining the situation at bugs.freenas.org and post the issue number here. Keep in mind that using the wizard to create shares is the recommended method, but it could be useful to have these attributes for existing shares.

 

[stualden]

Thank you - it's there now as #9342:

https://bugs.freenas.org/issues/9342

A little more testing revealed that the problem shows up only when creating the share, not when reviewing it later. So I took the liberty of calling it a bug and tightened up the description of the problem.